Procedural wrinkled paper lamp cycles material
Ok, so here's what I could come up with. This is what I could achieve with materials only. Not good enough for closeups, but perhaps enough for far-off objects or to save resources.



With modelling I got to this. It's not perfect, couldn't figure out a way to automatically make them not intersect, but its a reasonable time/effort/fidelity ratio.



Star of with an Icosphere, subdivide it enough, for the desired level of detail, then add a Decimate modifier.



Apply the decimate modifier, enter Edit Mode and in Edge Selection Mode with the Random Select operator select any number of edges around 50% to 60%.

Bevel those edges, then extrude them outwards with Alt + E > Region (Vertex Normals).





Add a Subsurf modifier on top, and you are good to go. Material is the same as above without all the texture work.



Additionally you may use Proportional Edit with a Random falloff type, to scale all vertex outwards, and/or rotate them slightly, and give it a more irregular look. Use a fake loose vertex, placed at the center of the sphere, selected for scaling, then use the 3D Cursor as center of transform and increase the influence radius as necessary.